CABasicAnimation:从左到右

Question

通过下面的代码，我可以从左到右动画一个CALayer

let imageLayer = CALayer()
imageLayer.frame = CGRect(x: 0, y: 500, width: 100, height: 70)
imageLayer.contents = UIImage(named: "first_image")?.cgImage

let animation = CABasicAnimation()
animation.keyPath = "position.x"
animation.fromValue = 100
animation.toValue = 300
animation.duration = 3
animation.fillMode = kCAFillModeForwards
animation.isRemovedOnCompletion = true
animation.repeatCount = 2
imageLayer.add(animation, forKey: "basic")

self.view.layer.addSublayer(imageLayer)

我想做的是

循环:1- "first_image“将从左向右移动。

和在

循环:2- "second_image“(这是另一幅图像)将从左向右移动，就像以前的循环一样。

在这里，循环: 1 +循环: 2实际上是一个动画，我希望这个动画发生很多次。如何做到这一点？如能提供任何协助，将不胜感激。

Answer 1

当您需要从左到右&反之亦然的动画，您也可以使用UIView.anima..动画。

     let testViewTowardsLeft = UIView(frame: CGRect(x: 0, y: 150, width: 50, height: 50))
    testViewTowardsLeft.backgroundColor = .red
    view.addSubview(testViewTowardsLeft)
    UIView.animate(withDuration: 1, delay: 0, options: .repeat, animations: {Bool in
        testViewTowardsLeft.frame = CGRect(x: 100, y: 150, width: 50, height: 50)

    }, completion: nil)


    let testViewTowardsRight = UIView(frame: CGRect(x: 100, y: 100, width: 50, height: 50))
    testViewTowardsRight.backgroundColor = .red
    view.addSubview(testViewTowardsRight)
    UIView.animate(withDuration: 1, delay: 0, options: .repeat, animations: {Bool in
        testViewTowardsRight.frame = CGRect(x: 0, y: 100, width: 50, height: 50)

    }, completion: nil)

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